Mathematics
If xi's are the class marks of the class-intervals of grouped data, fi's are the corresponding frequencies and x̄ is the mean, then Σ fi(xi − x̄) is equal to :
−1
0
1
2
If xi's are the class marks of the class-intervals of grouped data, fi's are the corresponding frequencies and x̄ is the mean, then Σ fi(xi − x̄) is equal to :
−1
0
1
2